Atasilp C.Lenavat R.Vanwong N.Chansriwong P.Sirachainan E.Reungwetwattana T.Jinda P.Aiempradit S.Sirilerttrakul S.Chamnanphon M.Puangpetch A.Sankuntaw N.Satapornpong P.Sukasem C.Mahidol University2023-06-182023-06-182022-07-15Frontiers in Oncology Vol.12 (2022)https://repository.li.mahidol.ac.th/handle/20.500.14594/83674Background: The two common methylenetetrahydrofolate reductase (MTHFR) polymorphisms 677G>A and 1298A>C may have been affecting 5-FU toxicity in cancer patients for decades. Drug efficacy has also been shown by previous studies to be affected. In this study, we investigated the effects of these polymorphisms on 5-FU hematological toxicity and treatment efficacy, to provide enhanced pharmacological treatment for cancer patients. Methods: This is a retrospective study involving 52 Thai colorectal cancer patients who were treated with 5-FU based therapy, using TaqMAN real-time PCR to genotype the MTHFR polymorphisms (677G>A and 1298A>C). The toxicity and response rate were assessed using standardized measures. Results: Neutropenia was significantly more likely to be experienced (P=0.049, OR=7.286, 95% CI=0.697-76.181) by patients with the MTHFR 677G>A polymorphism, in the same way as leukopenia (P =0.036, OR=3.333, 95%CI=2.183-5.090) and thrombocytopenia (P<0.001, OR=3.917, 95%CI=2.404-6.382). The MTHFR 1298A>C polymorphism had no statistical association with hematological toxicity in 5-FU treatment. The response rate to 5-FU was not significantly affected by these two polymorphisms. Conclusion: The MTHFR polymorphism 677G>A is a significant risk factor for developing leukopenia, neutropenia and thrombocytopenia as toxic effects of 5-FU therapy in cancer patients. Therefore, patients receiving 5-FU-based therapy should be aware of their polymorphisms as one risk factor for experiencing severe toxicity.Biochemistry, Genetics and Molecular BiologyArticleSCOPUS10.3389/fonc.2022.9166502-s2.0-851351727602234943X